This invention relates to replicated database network architecture. More particularly, the invention relates to providing even loadsharing of queries among the replicated databases in the network.
In the early 1980's, centralized databases called network control points (NCP) were introduced into signaling networks by AT&T to support the credit card calling service and 800 service. The network architecture with these network control points allowed intelligent network services for providing call handling information in response to network queries.
The network control points for the 800 service, for example, are deployed throughout the United States to support the Data Base 800 Service mandated by the Federal Communication Commission. In the network architecture for such 800 service, 800number calls are routed from a local router or end office to a network switch which launches network queries to the Network Control Point. The network control point translates the 800 number to a routing number and returns the routing number to the network switch. The network switch subsequently routes the call to an appropriate network carrier based on this routing number.
The network control points are designed to accommodate growth and additional services. For example, the network control points are designed as high-capacity systems handling more than one million queries per hour. Also, alternate billing services (ABS) such as a collect calling service and a bill-to-third number calling service have been implemented using the network control point architecture. The network control points comprise replicated databases containing the same records for reliability reasons against natural disasters such as fire and flood.
With an increasing number of communication services introduced into the network and increasingly sophisticated services, developing a scheme to insure that queries are handled evenly among available network control points is an important task. For example, where the control points comprising a set of replicated databases in the telecommunication network receive a large volume of queries that can be handled at any of the replicated databases, it is essential to direct incoming queries only to available databases.
It is therefore an object of this invention to provide reliable methods and networks that can handle a large volume of queries to the distributed applications.
It is a more particular object of this invention to provide methods and networks that can evenly loadshare queries amongst available databases containing the same software and data.